Objective:

The objective of this lab was to learn how to use Arduino Uno and Arduino IDE by implementing simple tasks. By the end we had a basic robot that could autonomously move back and forth and spin in place.

Team Division:

• Meghan Chen, Serena Krech, Alice Song
• Rohit Krishnakumar, Victoria Tu, Michael Yee

Materials used:

• 1 Arduino Uno
• 1 USB A/B cable
• 1 Continuous rotation servo
• 1 blue LED (could be any visible color)
• 1 Potentiometer
• Several resistors (kΩ range)
• 1 Solderless breadboard

Procedure:

1. Install the Arduino IDE
2. Test the built-in blink sketch
3. Modify the blink sketch to blink an external LED
4. Add a potentiometer to control brightness of the external LED
5. Check the duty cycle on oscilloscope
6. Use the potentiometer to control a continuous rotation servo motor
7. Assemble a robot and program it to run autonomously

1. Install the Arduino IDE:

• Before the lab, each of us downloaded Arduino IDE to our laptops.
• We read the documentation for the Parallax Continuous Rotation Servo and the Arduino Reference pages for additional help.

2. Testing the Built-in Blink Sketch:

• We tested the blink example code provided by the Arduino IDE (File > Examples > 1.Basics > Blink) to test the internal LED.
  

3. Testing Arduino Digital I/O Pins:

• We modified the sample internal blink code to blink the external blue LED.
• For each digital pin on the Arduino, we then connected a resistor and the blue LED in series in order to be sure that each pin was functional. The LED was connected in series with a resistor to control the current and protect the board.
  

4. Reading Potentiometer Using Serial Communication:

• We tested the serial communication between the Arduino and the laptop by inserting a Serial.begin(9600) command in the setup function and multiple Serial.println commands in the loop function.
• We then added a potentiometer to control the brightness of the LED by reading an analog input from A0.
  

5. Oscilloscope Reading of Potentiometer-Controlled LED Circuit:

• We hooked up the circuit to an oscilloscope to see the frequency and duty cycles of the signal as the potentiometer changed.

6. Potentiometer-Controlled Servo:

• We then edited the code to control the servo with the potentiometer.
  

7. Robot Demo:

• Our robot was programmed to turn, move forward, and move backward autonomously to simulate movements it would do in the maze.
• Our battery pack wasn’t charged, so we had our Arduino connected to a laptop, which only served as a power source.